Patent GB-409364-A (GB)
Title: Improvements in or relating to clutch-operating mechanism for motor vehicles
IPC: B60K23/02
Filed: 1932-10-31
Abstract: 409,364. Operating clutches. POLLAK, J. E., 20, Holborn, London.-(Borg & Beck Co. ; 6558, South Menard Avenue, Chicago, U.S.A.) Oct. 31, 1932, No. 30546. [Class 80 (ii).] Relates to clutch-operating mechanism of the kind comprising a suction-motor 23, Figs. 1 and 5, connected to the clutch lever 21 and controlled by valve mechanism, Figs. 3 and 4, including : (1) a main valve 59, 60 adapted to apply suction to the motor 23, or to vent it to atmosphere ; (2) a check valve 77 to retard the approach of the clutch elements at the instant prior to engagement; and (3) a bleed opening 82<1>, variable if desired by means of a valve, to control the final approach of the elements. According to the invention, the main valve 59, 60 is held in an intermediate position to close the bleed opening, so that the clutch elements are arrested when the check valve 77 closes ; and a release control is provided for re-opening the bleed opening-for example by resuming the movement of the main valve. In the form shown in Figs. 1, 3, and 4, the clutch pedal 21 is operated by a cable 40 connected through a rod 28 to a diaphragm 26 clamped between the two parts of the suction-motor casing 23, which is connected by a pipe 46, to the control valve mechanism 48, which in turn is connected through a flap valve 65 and pipe 74 to the induction pipe 11. On depressing the heel of the pedal 92, a pin 89 acts on the wire 57 of a Bowden cable 56 so as to raise the valve 59, 60 from the position shown to its highest position. The vessel 23 is thus connected to suction, so that the rod 28 is raised and the clutch disengaged. On releasing the pedal 92, a spring raises the pin 89 and rocks the pedal forward about its pivot 94 until its front end touches the accelerator pedal 20. The valve 59, 60 is thereby lowered to such an extent that the top of the piston 60 is between the bleed hole 82<1> and the inlet holes 78. Air enters the upper part of the chamber 23, and the diaphragm 26 and rod 28 descend. Just before the clutch engages, the valve 77, which is connected by a bracket 34 to the rod 28, covers the holes 78 and arrests the movement of the clutch. To complete the clutch-engagement, the pedal 92 is gradually rocked further forward to depress the accelerator pedal 20, thereby allowing the pin 89 to rise further, and the valve 59, 60 to be lowered further, so as gradually to uncover the bleed opening 82<1>. Air thus enters the motor 23 at a rate depending on the extent to which the accelerator pedal 20 is depressed. The flap valve 65 prevents any sudden rise of pressure in the induction pipe from affecting the pressure in the chamber 23. In the modified arrangement shown in Fig. 5, the control valve has a depending stem 96 spring-pressed into engagement with an operating lever 99, which is pivoted at 100 to a bracket on the dashboard and at 112 to a link 111 having a slot 110 in which works a pin 109 on the heel of the pedal 105, the arrangement being such that when the pedal is released after declutching, the pin 109 rises to the top of the slot and draws the lever 99 into such a position that the valve piston 60, Fig. 3, is in the " checking " position between the bleed hole 821 and opening 78. The necessary " lost-motion " is obtained by friction brakes 104 acting on the lever 99.